When Paypal requests an invoice ..

[IDV8]

Why do they ask? And what decides whether what we submit passes or is denied when we send it in?

[GreenBean]

Why do they ask? Because they dont like you.

What decides the reply? If they like you. Accounts get reviewed to determine the 'risk' or otherwise of their doing business with you.

It's all in their grubby sweaty hands, all power to them.

There are numerous things that happen to paypal accounts. Bottom line is paypal's reaction to protect themselves.
Invoices get supplied with success. You win.
Invoices get supplied with denial. paypal win.

Aim for your victory

[IDV8]

Does it matter who the invoice is supplied by? Or are they just looking to make sure you've purchased an item and have it in your possession as per the invoice? Just seems silly I mean, what if you picked up 10 t-shirts at a car boot sale, sold them on eBay and they expect an invoice from that? It isn't going to happen.. lol - Btw GB, reply to PM please? :D